1. Field of the Invention
This invention relates to a retractor with a take-up force reducing device which reduces tension in a take-up direction applied to a webbing during the wearing of the webbing and prevents any excessive pressure force from being applied to the webbing wearer's body.
2. Description of the Prior Art
Generally, a biasing force of considerable intensity in a take-up direction is applied to a take-up shaft in order that webbing drawn out from the retractor for wearing may be again fully taken up onto the take-up shaft in the retractor. Therefore, even during the wearing of the webbing, a strong biasing force in the take-up direction is applied to the webbing and a pressure force of considerable intensity is applied to the wearer, and this gives the wearer a sense of displeasure which forms a cause for the seat occupant to be unwilling to wear the seat belt in spite of the fact that wearing the seat belt is desirable in ensuring safety.
To solve this, it has been proposed to provide a retractor with a take-up force reducing device which places a part of biasing means for biasing the webbing into non-operative condition during the wearing of the webbing so as not to act on the take-up shaft and causes it to recover its operative condition when it is necessary to take up the webbing onto the take-up shaft in the retractor. In this case, however, there is a problem in that when the wearer tries to move and draw out the webbing while the reducing device is working, the reducing device acts as a strong resistance to the draw-out of the webbing and considerably hampers free movement of the wearer.
In order not to hamper free movement of the wearer, it has also been proposed to cause the reducing device to modify its operative condition intermittently and thereby lessen the resistance to the draw-out of the webbing, but in this case, the sound produced by impact or friction between the reducing device and a member on which it acts is a problem.
Further, in such a reducing device having a construction in which the biasing means for biasing the webbing is divided into a plurality of portions and these portions are coupled together by a connecting member, when the biasing means rapidly changes its condition, it may assume an abnormal form and may be urged against the take-up shaft or the connecting member to cause various inconvenient phenomena such as unsatisfactory take-up and the like.